1. Field of the Invention
The present invention relates to a retainer ring for securely retaining a first object, e.g., an adaptor or a bit, to a second object, e.g., a box end of a wrench or a shank of a screwdriver.
2. Description of the Related Art
FIG. 12A of the drawings illustrates a conventional retainer ring 1 engaged in an annular groove 3 of an object 2, e.g., an adaptor. After mounting on the object 2, the retainer ring 1 could move to a position shown in FIG. 12B under the action of gravity. This is because there is no means for securely retaining retainer ring 1 in the annular groove 3. As a result, as illustrated in FIG. 13, it would be impossible to mount the object 2 into a receiving compartment 4 of, e.g., a box end of a wrench, as the retainer ring 1 protrudes too much outward to be inserted into the receiving compartment 4.